is there difference if you pull a block down a hill or if you push a block down a hill. Or if you push a block up a hill or pull
it up ? For example if you PULL a block down a hill it would be F+Fg||-fk =ma (the force you are using +Fsinθ - kinetic friction =ma. Would this change if you PUSH the block down?
The answer is 2.49 x 10^5 KJ. This was obtained (1) use the formula for specific heat to achieve Q or heat then (2) get the energy to melt the copper lastly (3) Subtract both work and the total energy required to completely melt the copper bar is achieved.